This invention relates to endoscopes which can take photographs as combined with any photographing devices and more particularly to a hard endoscope having a relay lens system in the observing optical system.
Generally, a photographing device is fitted through a photographing adapter to the eyepiece part of an endoscope and, for example, a body cavity in which the inserted part of the endoscope is inserted is photograhed and diagnosed. However, if the optical axis of the endoscope and the optical axis of the photographing adapter or photograhing device do not coincide with each other and are eccentric from each other, the image obtained in the photographing device will differ from that seen by the endoscope. Therefore, the eccentricity of the optical axis of the endoscope side has been controlled by an eccentricity controlling means provided on the photographing device side. However, since the above mentioned eccentricity is different in each endoscope, it will be necessary to control the eccentricity whenever the above mentioned photographing device is fitted to the eyepiece part of each endoscope.
In order to solve this disadvantage, an image guide fixing device of an endoscope eyepiece part is disclosed in Japanese Utility Model Laid Open Publication No. 126801/1980. This device is so formed that, in a soft endoscope in which the observing optical system for transmitting images is formed of a fiber bundle, the above mentioned eccentricity is forcibly controlled, for example, with three-point lock screws by utilizing the flexibility of the above mentioned fiber bundle. However, in the hard endoscope in which images are transmitted by the relay lens system, it is impossible to forcibly easily adjust the image transmitting optical system as in the above mentioned device disclosed in Japanese Utility Model Laid Open Publication No. 126801/1980.
Further, as in the adapter device disclosed in U.S. Pat. No. 4,196,990, it is possible to control the above mentioned eccentricity by moving a vision field mask to a false focusing position. However, if the vision field mask is thus moved, the entire image will be deviated from the optical axis of the endoscope eyepiece and the resolving power and picture quality will be reduced. This is not desirable.